1. Field
Apparatuses and methods consistent with embodiments relate generally to a microfluidic device and a sample testing apparatus using the same and, more particularly, to a microfluidic device having multiple reaction chambers to contain a sample in order to reduce cross-contamination between the chambers, and a sample testing apparatus including the same.
2. Description of the Related Art
A variety of methods for analyzing samples have been developed in various applied fields such as environmental monitoring, food tests, and medical diagnosis. Existing test methods require numerous manual operations and various apparatuses. To perform a test according to a predetermined protocol, an experienced tester needs to manually perform a variety of steps such as reagent loading, mixing, separation and movement, reactions, and centrifuges, several times. Therefore, errors may be easily generated when obtaining results of the test.
Accordingly, an experienced clinical pathologist is needed to quickly perform a test. However, even an experienced clinical pathologist has lots of difficulties in simultaneously performing various tests. For example, in the diagnosis of an urgent case, a quick test result is very important for performing quick emergency treatment. Thus, there is a demand for an apparatus capable of quickly and accurately performing various pathological tests needed according to various situations.
A large and expensive automated apparatus is used for a related art pathological test and a relatively large amount of a test material such as blood is required. Accordingly, a test result may be issued from as long as two days to two weeks after the test material is obtained from a patient.
To address this problem, a compact and automated apparatus has been developed which may quickly analyze a test material(s) obtained from one or more patients if necessary. For example, when blood is loaded in a disk type microfluidic device and the disk type microfluidic device is rotated, serum is separated from the blood due to a centrifugal force. The separated serum is mixed with a predetermined amount of dilution buffer and moved to a plurality of reaction chambers in the disk type microfluidic device. Different reagents are previously loaded in the reaction chambers for different blood test items so that the different reagents react to the serum to present a predetermined color. Blood analysis may be performed by detecting a change in the color.
A device referred to as a “lab-on-a-chip” has a microfluidic structure mounted on a substrate in a chip form, such that some experiments involving biological or chemical reactions can be conducted on a small chip. The lab-on-a-chip is capable of executing several experimental processes and/or operations on the structure.
In order to move a fluid within the microfluidic structure, a driving pressure is generally required. The driving pressure may be a capillary pressure or pressure generated using an additional pump. In recent years, a disc-type microfluidic device, which is referred to as a “lab CD,” “lab-on-a-disc” or a digital bio disc (DBD), has been proposed. The disc-type microfluidic device has a microfluidic structure mounted on a disc-type body and uses centrifugal force to move a fluid in order to execute a series of tasks.
In general, the disc-type microfluidic device includes a chamber containing a fluid, a channel through which the fluid flows and a valve for controlling fluid flow, and may be fabricated by combining these components in different ways.
The disc-type microfluidic device may function as a sample testing apparatus to test a sample such as blood. Here, the disc-type microfluidic device may include a plurality of reaction chambers each containing a reagent to react with the sample. The sample inflow into the reaction chamber may react with the reagent contained in the reaction chamber and, by detecting the results of the reaction, a test result of the sample may be obtained.
However, during testing of the sample, contents in any one of the reaction chambers may flow into at least one other chamber adjacent to a first chamber (that is, the former), thus mixing with contents of the other chamber. This is referred to as “cross-contamination” and, as a result, reaction results of the reaction chamber may be unreliable, in turn reducing the reliability of the sample testing apparatus.
In order to reduce such cross-contamination, it is possible to increase a distance between each of the multiple reaction chambers and a provide a sample distribution channel to connect these chambers with one another. However, this is problematic in that it increases the overall size of the disc-type microfluidic device.